[vincnetas]

Why would it be difficult? Just copy paste content to different domains. And done. And for example if google decides to down rank sites that have same content on different domains, well, then you have a nice weapon against your competitors, just copy their sites lot of times and you got your competitor removed from google.

[ncruces]

It's a game of cat and mouse, and apparently all the “this is easy” people think they're just smarter than everyone out there.

[aaronwall]

One of my buddies that got into SEO a half decade before I did mentioned the copy and paste rankeroo stuff was real popular back in the days of Infoseek, Altavista, Excite, Lycos and similar.

Google looks for the canonical version of a document and then deduplicates before returning the result set.

You can add &filter=0 to the end of the search URL for a particular query to turn off the duplicate content filters.

An old school spam technique for some affiliates in the early days of Google was to buy a high PR link to their affiliate URL so that like site.com/?aff=123 would be the default version of the homepage & the branded searches for the merchant would then owe the affiliate the commissions until the rankings shifted again.

[jongjong]

Well surely the algorithm can detect duplicate content. Also Google should focus beyond content and consider user satisfaction metrics to decide what is above or below the threshold. Maybe AI can help with all these things?